Projectile.



No. 741,733. PATENTED OCT. 20, 1903;

E. T AS.

JE E.

APPLIO T FILED 11031.25, 1902.

550405; I OHM;

as improved projectile forms a part.

.0 shell separated from the projectile.

50 within the barrelof the gun.

NlTE STATES HENRY E. THOMAS, OF SAN FRANCISCO, CALIFORNIA.

PROJECTILE.

SPECIFICATION forming part of Letters Patent No. 741,738, dated October 20, 1903.

Application filed November 25, 1902. Serial No. 132,836. (No model) 7 State of California, have invented certain newand useful Improvements in Projectiles, of which the following is a specification.

My invention relates to improvements in projectiles, the object of my invention being to provide an improved projectile which can be discharged from a breech-loading gun and which will be given a rotary movement about its axis by means of its flight through the gun and air without the necessity of rifling the barrel of the gun to impart said rotary movement.

My invention therefore resides in the novel construction, combination, and arrangement of parts for the above ends hereinafter fully specified, and particularly pointed out in the claims. 7

In the accompanying drawings, Figure 1 is a side view of a cartridge adapted for use with a breech-loading gun and of which my Fig. 2 is a cross-section on the line A A of Fig. 1 looking in the direction of flight. Fig. 3 is an end view of the projectile separated from the shell of the cartridge. Fig. 4 is an end view of the shell separated from the projectile.

Fig. 5 is a cross-section on the line B B of Fig. 1. Fig. 6 is a side view of the projectile separated from the shell. Fig. 7 is a side view of the shell separated from the projectile.

5 Fig. 8 is a side view of a modified form of cartridge. Fig. 9 is a cross-section on the line 0 C of Fig. 8. Fig. 10 is an end view of the projectile in this modification separated from the shell. Fig. 11 is an end view of the Fig. 12 is a cross-section on the line D D of Fig. 8.

Referring to the drawings, 1 represents my improvedprojectile,and 2 the shell therefor. Said shell is provided with the usual flange 3,

whereby it retains its" position in a breechloading gun when the cartridge is discharged. The projectile has a shoulder 4, which abuts against the front end of the shell, so as to form a longitudinally smooth surface to fit The projectile has thus a rear cylindrical surface of somewhat less diameter than the front cylindrical in rotating the projectile.

surface, around which rear surface the shell fits snugly.

In order to impart rotation to the projectile, there are provided in the cylindrical surface thereof V-grooves 6, of which I have herein shown four in number, although any suitable number of such grooves may be provided. These grooves extend spirally along the projectile, and by the air-pressure against the sides of the grooves in the rapid flight of the projectile through the gun and air rotation is imparted thereto. In Fig. 1 the grooves are shown so formed as to impart a right-handed rotary movement to the projectile, and in this case the right sides 7 of said grooves, looking in the direction of flight, are made in surfaces radial or normal to the surface of the projectile. In other words, the forward sides of said grooves-in the rotary motion of the projectile are steeper than the rear sides thereof, and

i thus offer the greatest resistance to the airpressure, so that the grooves are most efiective The grooves increase in depthfrom front torear. The advan-' tage of this construction is twofold: First, the grooves have thus the greatest effieiency in rotating the projectile; secondly, the rear part of the projectile is made'lighter, thus as.- sisting in maintaining theprojectile straight in its course. The inner surfaceof'the shell is formed with ribs 8, which enter said grooves and fill up the same. These ribs 8 taper rear wardly to nothing. They have twofunctions; First, they prevent the gases of explosion from escaping through the grooves .at the instant of discharge; secondly, they impart an initial rotary movement to the projectile.

In Figs. 8 to 12 is shown a modified form of the invention, in which ribs 9 in theshell are formed by crimpingin the metal of the shell instead of forming said ribsso as to leave the shell with its exterior surface smooth, as in the former modification. In the latter modification also the grooves in the. projectile are so formed as to impart a lefthanded rotary movement, and it will readily be seen that rotation in either direction may equally well be obtained with my improved projectile.

By making my improved projectile with spiralgrooves either right handed or left handedit may be used with guns that have" IOO been rifled either to give a right-handed or a left-handed rotary motion. It can also be used with a gun in which the rifiing has be come smooth or worn out, and, in fact, my improved projectile will have a rotary motion whether discharged from a smooth-bore gun or from a new or an old rifled gun.

It is to be understood that the spiral grooves in my improved projectile, extending the whole length of the cylindrical surface of the projectile, are of importance, first, in combination with spiral ribs to impart to the projectile an initial rotary movement in the gun; secondly, to continue the said rotary movement in the barrel of the gun by reason of the air-pressure; thirdly, to continue the rotary movement of the projectile through the air afterit leaves the gun. For the above reasons my projectile may be used with a gun of longer barrel than heretofore, thereby enabling it to be discharged with greater force and to a greater distance and also more accurately.

It is to be noted that the obliquity of the grooves from the longitudinal direction of the projectile is only slight, the deviation of the groove from its front to its rear end being less than the distance between two adjacent grooves. This slight obliquity corresponds to the amount of obliquity in the riding of a gun.

1. In combination with a projectile having an annular shoulder near the rear end, and a reduced portion behind said shoulder and having V-grooves slightly oblique to the axisof the projectile, extending up to said shoulder, the forward sides of said grooves in the rotary motion of the projectile being steeper than the rear sides thereof, a shell containing an explosive, and provided with a rear shoulder for firing from a breech-loading gun, the mouth of the shell surrounding said reduced .portion of the projectile and said shell being conformed to close the openings in said shoulder made by the ends of said grooves, substantially as described.

2. In combination with a projectile having an annular shoulder near the rear end, and a reduced portion behind said shoulder and having V-grooves slightly-oblique to the axis of the projectile, extending up to and through said shoulder,the forward sides of said grooves in the rotary motion of the projectile being steeper than the rear sides thereof, a shell containing an explosive, and provided with a rear shoulder for firing from a breech-loading gun, the mouth of the shell surrounding said reduced portion of the projectile and said shell being conformed to close the openings in said shoulder made by the ends of said grooves, substantially as described.

3. In combination with a shell conformed for use with a breech-loading gun, a projectile having a cylindrical ,su rface, said surface being formed with spiral grooves increasing in depth from front to rear, substantially as described.

In witness whereof I have hereunto set my hand in the presence of two subscribing witnesses. t

H. E. THOMAS. 

